Hi @Dave59.

Welcome to the Sonos community and thanks for bringing this to our attention and for providing very detailed and isolated information about what was already done. I would like to  provide some recommendations to help you out.

I would suggest calling our technical support team for more in-depth troubleshooting steps, It is best that you be familiar with the following information so we can check our articles if we have a known issue with your network hardware since after doing a factory reset, your Sonos App still cannot add a Sonos device.

1. Router make and model.
2. Modem make and model.
3. Wifi booster or extender make and model.
4. Mesh system make and model.
5. Secondary or tertiary router make and model.
6. Other devices wired to the router.
7. Network switch or hub make and model.
8. Other devices wirelessly connected to the router.

Please let us know if you still have further questions or concerns. Here in the community, everybody can help you out.

Thanks,

Problem Solved! 5 Jan 2021

I called the tech support team...Hubert was very helpful, and very calm….easy to work with!

Solution was to reboot my Google Wifi mesh to ensure the speakers were operating on the correct channel.  

Thanks Hubert!!

Hi @Dave59.

Thanks for the immediate response, feedback and for sharing the solution on what solved the issue on your situation.  I’m glad that everything worked. This is a good read so other members of the community who might be have the same setup and issue as yours can find this thread helpful. I do hope you continue to love and enjoy your Sonos. 

Please do not hesitate to reach out or create a topic if you have additional questions or concerns. I’ll be more than happy to help.

Thanks,